Method of tempering leather, rubber, and composition soles and the like



Dec. 21 1926. 1,611,473

G. W. O. MARTIN METHOD OF TEMFERING LEATHER, RUBBER, AND COMPOSITION SOLES AND THE LIKE Filed Feb. 7, 1925 '.'E'.' Inz/eiwor: I 1% am;

-METHOD OF TEMPERING LEATHER, RUBBER, AND I LIKE.

Patented Dec. 21, 1926.

UNITED STATES PATENT OFFICE-a GILES W. O MARTIN, OF WEST MEDFORD, MASSACHUSETTS, ASSIGNOR T AMERICAN I SHOE MACHINERY COMPANY, OF EAST BOSTON, MASSACHUSETTS, A CORPORA- TION OF MASSAC HUSETTS.

Application filed February 7, 1925. Serial No. 7,670.

such for example, as leather, leather soles,

crepe rubber soles, composition soles and similar articles for tempering, impregnating and treating the same, and includes a simple,

novel and efficient apparatus for carrying out this method.

While my invention is primarily directed to the treating of such articles as leather soles in order to temper the same quickly,

expeditiously and to a predetermined extent,

yet the process may also be utilized advantageously for other purposes, wherein it is desired to impregnate an article or articles with any desired solution, for preserving, Softening, solidifying, coloring or other uses. The invention being directed pritnarily for treating leather soles by forcing tempering solution therein, I will describe the same as utilized in its preferred formfor this purpose.

It is at present customary in tempering leather, to moisten or soak the leather, particularly leather soles, in water or similar liquid, for a considerable time, and then the same are allowed to mull sometimes several-days in order to permit the soles to become sufliciently moist and to become tempered entirely through for use in sub sequent, manufacturing processes. Such leather soles are then operated upon in manufacturing boots and shoes, and fretpliently have to be again tempered, before t e numerous processes involved in shoe manufacturing, are completed. Itfis especially difficult in the case of turn shoes, for example, wherein the leather sole must .be in an unusually perfect temper to permit the turning operation without tearing out the stitches and destroying the shoe. Another method of tempering such articles, is that wherein a machine is employed, Which'both flexes, bends or works the leather, and simul taneously applies a tempering solution, thus effectually working the tempering solution into and through the leather, while also mechanically flexing it. The machine operation just described, is very much quicker than the former method, but some difiiculty has been found in the machine tempering method, because of the-continual variations in the amount and degree of moisture or solution which can, be applied to successive soles, during the short interval of time in which the sole is passing through the machine. The continual varying texture, density and condition and quality of the leather being operated upon, also presents a difliculty, and resulting in lack of uniformity in both the prior methods of tempering. By my presentprocess I eliminate the difficulties heretofore experienced, and by the application of a predetermined amount of pressure I am enabled to force, quickly, thoroughly and completely, into the leather soles or other articles being'treated, any desired amount of solution, tempering compound, coloring solution or treating liquid. This process, therefore, enables the tempering or treating operation, particularly on shoe soles of varying kinds or grades of leather, with a substantially predetermined extent of tempering, as desired, and in an extremely short time, and with the assurance of uniformity in the amount of solution applied to each article, while also insuring the complete penetration of the article being treated by the solution applied thereto. My process contemplates the positive forcing, by pressure appliance, of a solution into an article to be treated, as distinguished from prior tempering and treating methods, wherein the normal capillary attraction of the artiole was relied upon, or where, as in the said OMPOSITION SOLES AND THE machine operation, a combined working and,

moisture applying operation was employed.

In carrying out my invention, I have devised an extremely simple, inexpensive, and eflicient apparatus, which is much less expensive than any tempering machine of which I am aware, and which apparatus can be of any desired size, power and capacity, and of relatively compact form.

' A further object of my present improved apparatus is to provide pressure applying means which can be quickly filled wit articles to be tempered, hermetically sealed or substantially so sealed, quickly'subjected to the desired pressure, and instantly released after the predetermined time of pressure-applying for the particular articles being treated, has elapsed.

Referring to the drawings, illustrating my proved ;'ranged a pressure tank 1,of sufficient capacity to hold a substantial quantity of comfgessed air, preferably proportional to a r peated transferfrom the pressure tank 1 of relatively small quantities to a pressure treating tank 2. The pressure tank 1 is provided with a suitable gauge 3 and release valve 4 and may receive pressure'from an air pump 5, through the conduit 6, said air pump being actuated in anydesired manner,

such as, for example, from amotor 10, and belt 12, actuating the pump 5 from the.rota-. tion of the pulley l4 and shaft 15. 1

With a pressure tank 1 of substantial capacity, the motor-10 and pump 5 can be ops erated for a sufficient time, until the gauge 3 indicates a substantial-pressure, say five hundred pounds per square inch. 1 As in the present apparatus I may use a pressure,-

when operating upon sole leather for tempering, of from thirty pounds to 100 lbs. per square inch, and withdrawing the air necessary for the operation in small quantities from the tank 1.; when the. pressure tank 1 is thus charged itwill supply the apparatus for a considerable period, and for a number of successive treating operations.

My treating tank 2 may be of any suitable size, form, contqur and capacity, as herein illustrated being a simple, cylindrical member with a base 20 threaded or secured thereto, and a removable top 21, also threaded thereto. The base 20 carries abored and tapped recess 22, to receive the pipe 23 and connecting conduit 24 to the pressure tank 1 at 25. A valve 26 controls the release of pressure from the tank 1, anda gau' e 27 may be fitted to the conduit 24, to in icate the extent of pressure withdrawn from the tank 1.

At the top 21 is a release valve 30, and attached to the lowest point in the c0nduit'24 a valve 31 to permit withdrawal ofthe liquid or tempering solution from the treating tank 2.

When treating leather soles for temper-' ing, I first remove the cap 21, then fill the receptacle 2 with treating solution, to a suit'- ficient level 'to more than cover the soles. This solution may be water or any usual leather tempering solution and the same when partially filling the pressure receptacle 2 will also partially fill the conduit 24 up to a similar level therein,.which is referabl below the pressure gauge 27. As ere indicated, these. levels in the tank 2 and pipe 24 are, indicated at 33 and 34, which levels are those attained after the bunch of soles designated generally at 35, are placed in the treating tank.

' fastening 36. For my pressure treating, this fastening 36 may be left intact, if-desired,

as'the pressure applied is usually sufficient to permeate the entire thickness of the bunch of soles, and to percolate through the inters'tices between the layers of leather forming the bunch 35. If desired, however, the binder 36 may be cut, in .which case theindividual leather blanks will. fall partially apart, asindicated in dotted lines, Fig. 2, at 37 and 38. In either case a lurality of these articles are fitted within t e pressure tank 2, the cap 21 threaded thereon, a tight fit being insured by the use of a spanner if desired, engaging the recesses 39, 39, as indicated, and with the valves 30 and 31 shut. Thereupon the operator manipulates the valve 26 to open the same, permitting a flow of pressure from th tank 1, through the conduit 24 and pipe 3 into the interior of the treating tank 2. The indicator 27 will register the pressure attained, the first action being to force the compressed air against. the water level 34 in the conduit 24 downwardly, and either entirely out of the conduit 24, or the air will force thereby into the tank 2 and accumulate in the space above the liquid level 33, thus imparting desired pressure tothe liquid or tempering solution, which will simultaneously force the solution into the fibres or pores of the leather blanks 35 and compress or displace the .air therein contained, which latter may accumulate in the space above the liquid level 33. As soon as the gauge 27 registers the desired pres- Inc sure 30 to 100. lbs, for example, the valve and although greater pressure will insure quicker permeation, yet I believe it ordinarily desirable to supply a relatively slight pressure and proportionately prolong the application. Either method, however, can of course be employed and will be varied for different articles being treated. Furthermore, d ffering degrees of pressure and periods of time .to maintain t is pressure, will depend, not only upon the. article being so 1 treated, but also upon the solution ortreating liquid itself. Thus with a loose composition sole for example, and a relatively thick or viscous solution to be applied to same, the amount of pressure and the length of time can be increased or decreased as de sired for best results. Furthermore, I may vary the temperature in the treating tank 2' if desired, and may utilize to advantage, for some work, steam in place of compressed air, or of course any other gaseous liquid capable of transmitting pressure from a source of supply'to and into the tank 2. As soon as desired lapse of time for the particular work desired, and the cap 21 replaced and the operation repeated. I

I find that my pressure treating-process in the apparatus just described, when utilized on such articles as leather, is of special value, in that the tempering solution is positively forced into the leather, quickly and without other effort, or without disturbing the packages of the, leather. In fact, I can thus temper such a compound article as two sole blanks, united or cemented together by waterproof adhesive, through which no other tempering solution could be applied. By my method, I am enabled to positively force the tempering solution into both such sole mem bers of a cemented blank, and to thoroughly impregnate them with the tempering solution, and without disturbing the adhesion or cement, withdrawing the soles from the tank 2 ready for use.

As above explained, I believe that my present method is of distinct novelty, particularly -in forcing solutions, tempering compounds or the like liquids, into more or less solid substances. I find that this method and my apparatus as above described, can be employed for waterproofing materials, utilizing a rubber solution for this purpose if desired. Furthermore, I can use my present method and apparatus to great advantage in treating rubber soles, whether of vulcanized rubber or of crepe or unvulcanized rubber, whether a coating, treating, or solution, either for hardening or softening, is desired. My process and apparatus furthermore can be readily used where the application of heat is essential to the treatment of the articles, and without any expensive additions or changes.

My invention is further described-and defined in the form of claims as follows:

1. The improved method of tempering boot and shoe soles, which consists in immersing the sole to be tempered in a solution of tempering material, enclosing the same in a substantially airtight receptacle, and applying gaseous fluid under pressure for a time suflieient to force. the tempering solution into the sole, releasing the pressure and removing the sole.

2. The improved process of tempering boot and shoe soles of leather, composition or the like, which consists in applying a plurality of soles into a pressure receiving receptacle, supplying a quantity of tempering liquid in said receptacle, sealing the receptacle, applying air under pressure thereto, and maintaining said pressure to force the tempering solution into the soles, thereupon releasing the pressure, opening the receptacle and removing the tempered soles.

In testimony whereof, I have signed my name to this specification.-

GILES W. O. MARTIN. 

